PHOSPHOLIPID DISTRIBUTION AND PHOSPHOLIPID FATTY ACIDS IN FOUR SAUDI RED SEA SPONGES

Abstract

Sponge phospholipids and phospholipid fatty acids were investigated in sponges collected in Saudi Red Sea, namely Cinachyrella sp1, Cinachyrella sp2, Chalinula saudiensis and Stylissa carteri. More than fifty fatty acids have been identified as methyl esters and N-acyl pyrrolidides in each fatty acid mixture by GC/MS. The presence of bacteria was evidenced from the relatively high proportions of phosphatidylglycerol and phosphatidylinositol, and the high levels of the branched short-chain fatty acids. Cinachyrella sponges contained eighteen typical ?5,9 fatty acids, and new compounds, namely 17-methyltetracosanoic, 18-methyl tetracosanoic, 18-methylpentacosanoic, 18-methylhexacosanoic, 18,24-dimethylheptacosanoic and 6-bromo-?5,9-nonacosadienoic acids. Phospholipid fatty acids from Stylissa carteri were characterised by a high content of ?5,9 fatty acids (55.5 %) and phytanic acid (20 %). Chalinula saudiensis contained several ?5,9 fatty acids, including the rare 6-bromo-?5,9octacosadienoic acid. Unexpected polyunsaturated fatty acids occurred in the two latter sponges, such as arachidonic and docosahexaenoic acids.